Ideal gas: Energy

From SklogWiki
Revision as of 14:46, 9 May 2008 by Dduque (talk | contribs) (link added)
Jump to: navigation, search

The energy of the ideal gas is given by (Hill Eq. 4-16)

E = -T^2 \left. \frac{\partial (A/T)}{\partial T} \right\vert_{V,N} = kT^2 \left. \frac{\partial \ln Q}{\partial T} \right\vert_{V,N}= NkT^2 \frac{d \ln T^{3/2}}{dT} = \frac{3}{2} NkT

This energy is all kinetic energy, 1/2 kT per degree of freedom, by equipartition. This is because there are no intermolecular forces, thus no potential energy.


  1. Terrell L. Hill "An Introduction to Statistical Thermodynamics" 2nd Ed. Dover (1962)